Aircraft electric actuator drive apparatus

ABSTRACT

An aircraft electric actuator drive apparatus has an electric actuator and a secondary power supply device. The electric actuator is driven using electric power from a main power unit provided in an aircraft. The secondary power supply device can temporarily supply electric power to the electric actuator while electric power from the main power unit is applied to the electric actuator.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2013-180119. The entire disclosure of Japanese Patent Application No.2013-180119 is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an aircraft electric actuator driveapparatus.

2. Description of Related Art

Various electric devices are installed in an aircraft, and these devicesare driven by an electric motor mounted in the aircraft, for example. Anexample of the aforementioned devices is an electric-hydraulic pump forsupplying pressure oil to a hydraulically operated actuator that drivesmoving surfaces, as disclosed in JP2011-247334 A.

Note that moving surfaces include primary flight control surfacesconfigured as control surfaces such as an aileron, a rudder, and anelevator, and secondary flight control surfaces configured as a flap, aspoiler, and the like. Other examples of the aforementioned devicesinclude an electric actuator that drives the aforementioned movingsurfaces, legs (mechanisms that support an airframe of an aircraft onthe ground) of landing gear (undercarriage), and the like.

An electric actuator is also known as an actuator that drives movingsurfaces. An electric actuator has a screw mechanism, for example, and arod in the screw mechanism is displaced due to the driving force of anelectric motor.

A moving surface is displaced by this displacement of the rod.

For example, the electric motor in the aforementioned electric actuatorrequires a large current (inertial acceleration current) in order tostart displacement of a moving surface. That is to say, when starting anoperation of the electric motor, a large current (transient current)needs to be generated instantaneously in order to generate an inertialacceleration current. Moreover, in the case of simultaneously operatinga plurality of electric actuators, a plurality of electric motorssimultaneously begin to operate, and a larger current needs to begenerated instantaneously in an aircraft.

For this reason, in general, an aircraft has a large power unit forgenerating the aforementioned large current. Consequently, the grossweight of the airframe of an aircraft increases. Since there issignificant demand for a reduction in aircraft weight, there issignificant demand to further reduce the weight of the devices in theaircraft.

In view of the foregoing situation, an object of the present inventionis to provide an aircraft electric actuator drive apparatus with which alarge amount of electric power can be supplied to an electric actuatorand an increase in the size of a power unit can be suppressed.

SUMMARY OF THE INVENTION

(1) An aircraft electric actuator drive apparatus according to an aspectof the present invention for achieving the above-stated object includes:an electric actuator driven using electric power from a main power unitprovided in an aircraft; and a secondary power supply device capable oftemporarily supplying electric power to the electric actuator whileelectric power from the main power unit is applied to the electricactuator.

With this configuration, there are cases where a large current (inertialacceleration current) is temporarily required for the electric actuatorto begin to operate. In these cases, the secondary power supply devicecan supply electric power to the electric actuator. Therefore, theaforementioned large current can be supplied to the electric actuator asa result of electric power being output to the electric actuatorsimultaneously from the main power unit and the secondary power supplydevice. Accordingly, the aforementioned large current does not need tobe generated using only the main power unit. Therefore, the rated outputof the main power unit does not need to be increased to the extent thatthe main power unit can instantaneously supply a required large currentto the electric actuator, and the rated output can be further reduced.Thus, the size (weight) of the main power unit, the engine serving as amotor for driving the main power unit, and the like can be furtherreduced. As a result, with this configuration, the aircraft electricactuator drive apparatus can be provided with which a large amount ofelectric power can be supplied to the electric actuator and an increasein the size of the power unit can be suppressed.

(2) Preferably, the aircraft electric actuator drive apparatus furtherincludes a secondary power supply control device for controlling thesecondary power supply device, wherein the secondary power supplycontrol device operates the secondary power supply device in accordancewith necessary electric power required for an operation of the electricactuator.

With this configuration, the secondary power supply control device canset the amount of electricity discharge from the secondary power supplydevice in accordance with the state of power consumption by the electricactuator. Thus, electric power generated by the secondary power supplydevice can be used more efficiently. Consequently, the secondary powersupply device does not require an unnecessarily large rated output.Accordingly, the size of the secondary power supply device can befurther reduced.

(3) More preferably, the secondary power supply control device detects aload of the electric actuator, and operates the secondary power supplydevice in accordance with a result of the detection.

With this configuration, an output appropriate for the load of theelectric actuator can be supplied from the secondary power supply deviceto the electric actuator. For example, the secondary power supplycontrol device supplies electric power required by the electric actuatorto the electric actuator using feedforward control, and a voltagedecrease in the electric actuator can thereby be more reliablysuppressed.

(4) Preferably, a plurality of the electric actuators are provided, andthe secondary power supply control device can operate the secondarypower supply device based on a total value of necessary electric powerrequired for operations of the respective electric actuators.

With this configuration, even if the plurality of electric actuatorsoperate simultaneously, a larger amount of electric power than theamount applied from the main power unit can be supplied to the electricactuators. Furthermore, the electric power applied to the electricactuators can be collectively controlled by one secondary power supplycontrol device. Thus, the secondary power supply control device cancontrol the secondary power supply device using combined informationfrom the electric actuators. Accordingly, the secondary power supplycontrol device can perform electric power control for the electricactuators with more accuracy.

(5) Preferably, a motor driver that distributes electric power to theelectric actuator and outputs a signal for specifying an operationalstate of the electric actuator to the secondary power supply controldevice is further included, and the secondary power supply controldevice and the motor driver are separately disposed.

With this configuration, the secondary power supply control device andthe motor driver can be separately disposed. Thus, the secondary powersupply control device and the motor driver can be maintainedindividually. Accordingly, the maintainability of the aircraft electricactuator drive apparatus can be further enhanced.

(6) More preferably, the electric actuator includes a movable portionand an electric motor that operates the movable portion, and the movableportion, the electric motor, and the motor driver are disposed adjacentto one another.

With this configuration, as a result of adjacently disposing the movableportion, the electric motor, and the motor driver, the movable portion,the electric motor, and the motor driver can be maintained collectively.Accordingly, the maintainability of the aircraft electric actuator driveapparatus can be further enhanced.

(7) Preferably, the aircraft electric actuator drive apparatus furtherincludes an electric actuator control device that controls the electricactuator, and the electric actuator control device and the secondarypower supply control device are formed integrally.

With this configuration, the electric actuator control device and thesecondary power supply control device can share information, and thecontrol accuracy for the electric actuator and the control accuracy forthe secondary power supply device can be further increased. Furthermore,the overall size of the electric actuator control device and thesecondary power supply control device can be reduced.

(8) Preferably, the aircraft electric actuator drive apparatus furtherincludes an electric actuator control device that controls the electricactuator, wherein a plurality of the electric actuators are provided,and the electric actuator control device can control operations of theelectric actuators and output a signal for specifying an operationalstate of the electric actuators to the secondary power supply controldevice.

With this configuration, the electric actuator control device canconfigure an integrated system having a function of controlling theelectric actuators and a function of giving data for controlling theelectric actuators to the secondary power supply control device.

(9) Preferably, the secondary power supply device has aninverter-controlled power supply device.

With this configuration, since regenerative electric power from theelectric actuator can be returned to the secondary power supply device,energy saving in the electric actuator can be realized through a furtherincrease in electric power use efficiency. Moreover, a reduction in theamount of heat generated in the electric actuator can be realized.

(10) Preferably, the secondary power supply device includes a flywheelbattery.

With this configuration, the secondary power supply device can supplyelectric power to the electric actuator by converting kinetic energygenerated by a rotation of a flywheel into electric power. With thisconfiguration, by rotating the flywheel and storing kinetic energy inthe flywheel in advance, a large current can be instantaneously appliedfrom the secondary power supply device to the electric actuator when alarge current needs to flow through the electric actuator. That is tosay, a secondary power supply device with a high responsiveness withrespect to an electricity discharge request can be realized.

(11) Preferably, the electric actuator includes an electric actuator fora flight control system for controlling a flight of the aircraft.

With this configuration, a large current can be applied from the mainpower unit and the secondary power supply device to the electricactuator for a flight control system that receives a large drivingresistance during a flight of the aircraft. Accordingly, the electricactuator for a flight control system can be operated with a largerforce.

Note that the above and other objects, features, and advantages of thepresent invention will become apparent by reading the followingdescription with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a part of an aircraft having anelectric power system according to a first embodiment of the presentinvention.

FIG. 2 is a schematic view of a configuration of the electric powersystem.

FIG. 3 is a schematic view showing a configuration of a flight controlcomputer and an aileron drive apparatus.

FIG. 4 is a diagram showing an exemplary map for illustrating propertiesof electric power that is needed at the time of driving an electricmotor in an electric actuator.

FIG. 5 is a flowchart for illustrating an exemplary flow of processingin an aileron control device.

FIG. 6 is a flowchart for illustrating an exemplary flow of processingin a flywheel battery control device.

FIG. 7 is a schematic view for illustrating a main part of a secondembodiment of the present invention.

FIG. 8 is a schematic view for illustrating a main part of a thirdembodiment of the present invention.

FIG. 9 is a schematic view for illustrating a modification of the thirdembodiment of the present invention.

FIG. 10 is a schematic view showing a main part of a fourth embodimentof the present invention.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment

Hereinafter, a mode for carrying out the present invention will bedescribed with reference to the drawings.

FIG. 1 is a schematic view showing a part of an aircraft 100 having anelectric power system 1 according to a first embodiment of the presentinvention. Note that FIG. 1 shows a front part and an intermediate partof an airframe 101 of the aircraft 100, and omits a rear part of theairframe 101. FIG. 2 is a schematic view of a configuration of theelectric power system 1.

Referring to FIG. 1, the aircraft 100 is a passenger aircraft, forexample. The aircraft 100 includes the airframe 101, a pair of engines103L and 103R, namely a left engine 103L and a right engine 103R, andthe electric power system 1.

The airframe 101 has a body 104 and a pair of main wings 102L and 102R,namely a left main wing 102L and a right main wing 102R, connected tothe body 104.

The main wings 102L and 102R are provided with ailerons 105L and 105Rand spoilers 106L and 106R, respectively, as control surfaces. Theailerons 105L and 105R and the spoilers 106L and 106R are operated bylater-described electric actuators 41 and 51 and the like.

The engines 103L and 103R are jet engines for applying a propellingforce to the airframe 101, for example, and are turbofan engines in thepresent embodiment. The engines 103L and 103R are attached to the mainwings 102L and 102R, respectively. The engines 103L and 103R each have arotary shaft (not shown). The engines 103L and 103R are also used togenerate electric power to be consumed in the electric power system 1.

Note that in the electric power system 1, a configuration related to aleft board part of the airframe 101 is similar to a configurationrelated to a right board part of the airframe 101. Accordingly, in thepresent embodiment, the configuration related to the left board part ofthe airframe 101 in the electric power system 1 will be mainlydescribed, and part of the description of the configuration related tothe right board part of the airframe 101 in the electric power system 1will be omitted.

Referring to FIGS. 1 and 2, the electric power system 1 in the presentembodiment has a smart grid function, and electric power interchangeamong later-described DC buses 10 can be performed. The electric powersystem 1 also has an integrated electric power management system usingthe DC buses 10 and a smart meter function, and is configured tooptimize electric power supply in accordance with the operational stateof a later-described electric actuator 41.

Thus, the electric power system 1 in the present embodiment isconfigured to be able to efficiently supply and distribute electricpower, thereby achieving a reduction in the life cycle cost (LCC) of theaircraft 100. A specific configuration of the electric power system 1will now be described.

The electric power system 1 has a plurality of DC buses 10 (11 to 16), aplurality of main power units 21, 22, and 23, an external power supplyconnection unit 24, an auxiliary power unit (APU) 25, a ram air turbine(RAT) 26, a flywheel battery (FWB) 27, a battery 28, and a fuel battery29.

Each of the DC buses 10 (11 to 16) is an electric power system componentthat is provided in order to distribute electric power to a load(electric device), and is formed using electric wires or the like.

The DC buses 10 each have a first high-voltage bus 11, a secondhigh-voltage bus 12, an emergency high-voltage bus 13, an FCS (flightcontrol system) high-voltage bus 14, a medium-voltage bus 15, and alow-voltage bus 16. All these DC buses 11 to 16 are used to distributeDC power.

The high-voltage buses 11 to 14 are buses for high-voltage power, andare provided for 270-V DC power in the preset embodiment. The FCShigh-voltage bus 14 is provided as a DC bus for a flight control system,and is configured to distribute electric power to devices (an electricmotor 43 in a later-described aileron drive apparatus 40, etc.) relatedto flight control for the airframe 101, among electric devices.

On the other hand, among the buses 10, the buses 11 to 13, 15, and 16other than the FCS high-voltage bus 14 are provided in order to supplyelectric power to electric devices other than flight control devices.The first high-voltage bus 11 and the second high-voltage bus 12 areconfigured to distribute electric power to devices that are not directlyrelated to attitude control for the airframe 101, among high-voltage (DC270-V) electric devices.

The first high-voltage bus 11 is connected to, an air conditioner 31serving as an electric device, for example, and supplies electric powerto this air conditioner 31. The air conditioner 31 is used fortemperature adjustment in a passenger cabin of the airframe 101. Notethat, although not shown, the first high-voltage bus 11 is alsoconnected to a plurality of electric devices other than the airconditioner 31.

The first high-voltage bus 11 is electrically connected to themedium-voltage bus 15 via a switch 18 a and a DC/DC converter 19 a, anddistributes electric power to the medium-voltage bus 15 by the switch 18a being turned on. Note that each switch 18 is a switch for switchingbetween a conductive state and an insulating state. The voltage of theelectric power to be distributed from the first high-voltage bus 11 tothe medium-voltage bus 15 is lowered to the voltage for themedium-voltage bus 15 by the DC/DC converter 19 a, and is thereaftersupplied to the medium-voltage bus 15.

The first high-voltage bus 11 is also electrically connected to thelow-voltage bus 16 via a switch 18 b and a DC/DC converter 19 b, anddistributes electric power to the low-voltage bus 16 by the switch 18 bbeing turned on. Note that the voltage of the electric power to bedistributed from the first high-voltage bus 11 to the low-voltage bus 16is lowered to the voltage for the low-voltage bus 16 by the DC/DCconverter 19 b, and is thereafter supplied to the low-voltage bus 16.

The second high-voltage bus 12 is connected to, for example, an electricfuel pump 32 serving as an electric device, and supplies electric powerto this electric fuel pump 32. The electric fuel pump 32 includes anelectric motor for driving a pump, and is installed in a fuel tank (notshown) within the main wing 102L. The electric fuel pump 32 is driven inorder to supply fuel in the fuel tank to the engines 103L and 103R. Notethat, although not shown, the second high-voltage bus 12 is alsoconnected to a plurality of electric devices other than the electricfuel pump 32.

The second high-voltage bus 12 is also electrically connected to themedium-voltage bus 15 via a switch 18 c and a DC/DC converter 19 a, anddistributes electric power to the medium-voltage bus 15 by the switch 18c being turned on. Note that the voltage of the electric power to bedistributed from the second high-voltage bus 12 to the medium-voltagebus 15 is lowered to the voltage for the medium-voltage bus 15 by theDC/DC converter 19 a, and is thereafter supplied to the medium-voltagebus 15.

The second high-voltage bus 12 is also electrically connected to thelow-voltage bus 16 via a switch 18 d and the DC/DC converter 19 b, anddistributes electric power to the low-voltage bus 16 by the switch 18 dbeing turned on. Note that the voltage of the electric power to bedistributed from the second high-voltage bus 12 to the low-voltage bus16 is lowered to the voltage for the low-voltage bus 16 by the DC/DCconverter 19 b, and is thereafter supplied to the low-voltage bus 16.

The emergency high-voltage bus 13 is provided as an emergency bus, andfor example, when there is an abnormality in at least one of the firsthigh-voltage bus 11, the second high-voltage bus 12, and the low-voltagebus 16, the emergency high-voltage bus 13 is configured to distributeelectric power to the first high-voltage bus 11, the second high-voltagebus 12, and the low-voltage bus 16 in which the abnormality occurred.

The emergency high-voltage bus 13 is connectable to the firsthigh-voltage bus 11 via a switch 18 e, and distributes electric power tothe first high-voltage bus 11 by the switch 18 e being turned on.Similarly, the emergency high-voltage bus 13 is connectable to thesecond high-voltage bus 12 via a switch 18 f, and distributes electricpower to the second high-voltage bus 12 by the switch 18 f being turnedon. The emergency high-voltage bus 13 is also connected to thelow-voltage bus 16 via a switch 18 g and the DC/DC converter 19 b, anddistributes electric power to the low-voltage bus 16 by the switch 18 gbeing turned on. Note that the voltage of the electric power to bedistributed from the emergency high-voltage bus 13 to the low-voltagebus 16 is lowered to the voltage for the low-voltage bus 16 by the DC/DCconverter 19 b, and is thereafter supplied to the low-voltage bus 16.

The FCS high-voltage bus 14 is connected to the electric actuator 41 inthe aileron drive apparatus 40 serving as an electric device included inthe flight control system. The FCS high-voltage bus 14 is also connectedto the electric actuator 51 in a spoiler drive apparatus 50 serving asan electric device included in the flight control system.

The FCS high-voltage bus 14 is also electrically connected to thelow-voltage bus 16 via a switch 18 h and a DC/DC converter 19 c, anddistributes electric power to the low-voltage bus 16 by the switch 18 hbeing turned on. Note that the voltage of the electric power to bedistributed from the FCS high-voltage bus 14 to the low-voltage bus 16is lowered to the voltage for the low-voltage bus 16 by the DC/DCconverter 19 c, and is thereafter supplied to the low-voltage bus 16.

The medium-voltage bus 15 is provided in order to distribute 120-V DCpower, for example. A heater 34 serving as an electric device thatoperates at the same voltage as that of the medium-voltage bus 15 isconnected to the medium-voltage bus 15. Note that the medium-voltage bus15 is also connected to a plurality of electric devices other than theheater 34.

The low-voltage bus 16 is provided in order to distribute 28-V DC power.The low-voltage bus 16 is connected to electric devices that operate atthe same voltage as that of the low-voltage bus 16. The low-voltage bus16 is connected to a flight control computer (FCC) 33 and the like thatserve as electric devices included in the flight control system.

The DC buses 10 having the above-described configuration are configuredsuch that electric power can be supplied thereto from the main powerunits 21, 22, and 23, the external power supply connection unit 24, theauxiliary power unit 25, the ram air turbine 26, the flywheel battery27, the battery 28, and the fuel battery 29.

The main power units 21, 22, and 23, the auxiliary power unit 25, theram air turbine 26, the flywheel battery 27, the battery 28, and thefuel battery 29 are provided as power supply devices, and are configuredto supply electric power to be consumed in the electric power system 1.Note that although the main power units 21, 22, and 23, the auxiliarypower unit 25, the ram air turbine 26, the battery 28, and the fuelbattery 29 are provided as elements of the electric power system 1 inthe present embodiment, this need not be the case. The main power units21, 22, and 23, the auxiliary power unit 25, the ram air turbine 26, thebattery 28, and the fuel battery 29 do not have to be included in theelectric power system 1.

The main power units 21, 22, and 23 are provided as main power supplydevices, and are AC power units in the present embodiment. The mainpower units 21, 22, and 23 are driven by the engine 103L for applying athrust force to the aircraft 100.

The main power unit 21 is provided mainly as a power unit dedicated tothe flight control system. The main power unit 21 is configured to bedriven by the rotational force of the rotary shaft of the engine 103L.AC power generated by the main power unit 21 is converted intohigh-voltage (270-V) DC power by an AC/DC converter 20 a, and isthereafter supplied to the FCS high-voltage bus 14.

The main power unit 22 is configured to be driven by the rotationalforce of the rotary shaft of the engine 103L. AC power generated by themain power unit 22 is converted into high-voltage DC power by an AC/DCconverter 20 b, and is thereafter supplied to the first high-voltage bus11 via switches 18 i and 18 j. The AC power generated by the main powerunit 22 is also supplied to the second high-voltage bus 12 via the AC/DCconverter 20 b and switches 18 i, 18 k, and 18 l.

The main power unit 23 is configured to be driven by the rotationalforce of the rotary shaft of the engine 103L. AC power generated by themain power unit 23 is converted into high-voltage DC power by an AC/DCconverter 20 c, and is thereafter supplied to the first high-voltage bus11 via switches 18 m, 18 k, and 18 j. The AC power generated by the mainpower unit 23 is also supplied to the second high-voltage bus 12 via theAC/DC converter 20 c and the switches 18 m and 18 l. The AC powergenerated by the main power unit 23 can also be supplied to theauxiliary power unit 25 via the AC/DC converter 20 c, switches 18 n and18 o, and an AC/DC converter 20 e. The electric power is supplied fromthe main power unit 23 to the auxiliary power unit 25 when, for example,the auxiliary power unit 25 is activated.

The auxiliary power unit 25 is provided as an auxiliary power supplydevice, and is a gas turbine engine in the present embodiment. Note thatthe auxiliary power unit 25 may be formed using a different motor, suchas a diesel engine. The auxiliary power unit 25 is activated usingelectric power from the main power unit 23 or electric power from thebattery 28. The electric power from the main power unit 23 or theelectric power from the battery 28 is converted from DC power into ACpower by the AC/DC converter 20 e, and is supplied to the auxiliarypower unit 25.

Upon the auxiliary power unit 25 being activated, electric power isgenerated by a power unit provided in the auxiliary power unit 25. Theelectric power generated by the auxiliary power unit 25 is applied to apower line starting from the main power unit 23, via the AC/DC converter20 e and switches 18 o′ and 18 n, and can thereby be supplied to thefirst high-voltage bus 11 and the second high-voltage bus 12. The ramair turbine 26 is configured to start electric power generation ifabnormalities occur in the auxiliary power unit 25 and the main powerunits 21, 22, and 23 during a flight of the aircraft 100.

The ram air turbine 26 is provided as an emergency power unit. The ramair turbine 26 includes an AC power unit and a turbine that jumps outfrom the airframe 101 in the case where abnormalities occur in theauxiliary power unit 25 and the main power units 21, 22, and 23 during aflight of the aircraft 100. The AC power unit in the ram air turbine 26is configured to generate electric power by this turbine receiving windforce and rotating. The AC power generated by the ram air turbine 26 isconverted into DC power by an AC/DC converter 20 f, and is supplied tothe emergency high-voltage bus 13 via a switch 18 p and also to the FCShigh-voltage bus 14 via a switch 18 q.

The external power supply connection unit 24 is provided in order toreceive electric power from the outside of the aircraft 100 when theaircraft 100 is parked (stopped), for example. The external power supplyconnection unit 24 is configured to be connectable to power supplyequipment in an airport, for example. AC power applied from the externalpower supply connection unit 24 is converted into DC power by an AC/DCconverter 20 d, and is thereafter supplied to the first high-voltage bus11 and the second high-voltage bus 12 via switches 18 r, 18 s and 18 t.

The flywheel battery 27 is provided as an electricity storage device(secondary power supply device) capable of storing and dischargingelectricity, and is an inverter-controlled power supply device in thepresent embodiment. The flywheel battery 27 is an energy converterdevice that performs conversion between kinetic energy and electricpower, and is configured to be able to store electric power as kineticenergy.

The flywheel battery 27 has a function of an accumulator thattemporarily stores electricity. In the present embodiment, the flywheelbattery 27 is configured to be able to temporarily supply electric powerto the electric actuator 41 while electric power from the main powerunit 21 is applied to the electric actuator 41.

The flywheel battery 27 is connectable to the first high-voltage bus 11via a switch 18 u, and is also connectable to the FCS high-voltage bus14 via a switch 18 v. The flywheel battery 27 is configured such thatelectric power can be supplied thereto from the first high-voltage bus11 and the FCS high-voltage bus 14, and is configured to be able tosupply electric power to the first high-voltage bus 11 and the FCShigh-voltage bus 14. As a result of this configuration being employed,the first high-voltage bus 11 and the FCS high-voltage bus 14 areconnected to each other by the flywheel battery 27 so as to be able totransmit and receive electric power.

With the above configuration, the DC buses 10 are configured such thatit is possible for the DC buses 10 to always be electrically connectedto two or more types of power supply devices having different forms.Specifically, the first high-voltage bus 11 is configured such that itis possible for the first high-voltage bus 11 to always be connected tothe main power units 22 and 23 and the flywheel battery 27. The FCShigh-voltage bus 14 is configured such that it is possible for the FCShigh-voltage bus 14 to always be connected to the main power unit 21,the flywheel battery 27, and the fuel battery 29.

FIG. 3 is a schematic view showing a configuration of a flight controlcomputer 33 and the aileron drive apparatus 40. Referring to FIGS. 1 to3, the flywheel battery 27 forms a flywheel battery unit 60 togetherwith a flywheel battery control device 35. In other words, the flywheelbattery unit 60 has the flywheel battery 27 and the flywheel batterycontrol device 35.

The flywheel battery 27 has a flywheel 271, a motor generator 272, afirst inverter/converter 273, a second inverter/converter 274, and aninterface unit 275.

The flywheel 271 is provided as a kinetic energy accumulating member,and is configured to rotate and thereby store kinetic energy. Theflywheel 271 is connected to a rotary shaft of the motor generator 272and rotates together with this rotary shaft.

The motor generator 272 has a rotor, the aforementioned rotary shaftcapable of rotating integrally with the rotor, and a stator thatsurrounds the rotor. When electric power is applied to the motorgenerator 272, the motor generator 272 operates as a motor and therebyrotates the rotary shaft and rotates the flywheel 271. Thus, kineticenergy is accumulated in the flywheel 271. On the other hand, whenkinetic energy (rotational energy) of the flywheel 271 is applied to themotor generator 272, the motor generator 272 operates as a power unit,and outputs AC power to the first inverter/converter 273 or the secondinverter/converter 274.

The first inverter/converter 273 and the second inverter/converter 274are configured to convert DC power into AC power when DC power isapplied thereto, and to convert AC power into DC power when AC power isapplied thereto.

The first inverter/converter 273 is connected to the motor generator 272and the FCS high-voltage bus 14. If a predetermined control signal isgiven from the flywheel battery control device 35 to the firstinverter/converter 273 via the interface unit 275, the firstinverter/converter 273 can convert AC power from the motor generator 272into DC power and output this DC power to the FCS high-voltage bus 14.

The second inverter/converter 274 is connected to the motor generator272 and the first high-voltage bus 11. If a predetermined control signalis given from the flywheel battery control device 35 to the secondinverter/converter 274 via the interface unit 275, the secondinverter/converter 274 can convert DC power from the first high-voltagebus 11 into AC power and output this AC power to the motor generator272. The first inverter/converter 273 and the second inverter/converter274 are controlled by the flywheel battery control device 35. Aconfiguration of the flywheel battery control device 35 will bedescribed later.

The battery 28 is a secondary battery such as a lithium-ion storagebattery. The battery 28 is connected to the auxiliary power unit 25 viaa switch 18 w and the AC/DC converter 20 e. The battery 28 supplieselectric power to the auxiliary power unit 25 when, for example, themain power units 22 and 23 are not driven and the auxiliary power unit25 is activated. The battery 28 is also connected to the low-voltage bus16 via a switch 18 x, and can supply electric power to the low-voltagebus 16.

The fuel battery 29 is provided mainly as a power supply device used incase of emergency, such as when electric power supply from the mainpower units 21, 22, and 23 to the FCS high-voltage bus 14 is shut off.The fuel battery 29 is a battery that generates electric power by usingan electrochemical reaction. The fuel battery 29 cooperates with theflywheel battery 27 and the battery 28 to form a decentralized powersupply device. The fuel battery 29 is connectable to the emergencyhigh-voltage bus 13 via a switch 18 y, and can supply electric power tothe emergency high-voltage bus 13. The fuel battery 29 is connected tothe FCS high-voltage bus 14 via a switch 18 z, and can supply electricpower to the FCS high-voltage bus 14.

Next, a description will be given of a more detailed configuration ofthe aileron drive apparatus 40 and the spoiler drive apparatus 50provided in the electric power system 1. The aileron drive apparatus 40and the spoiler drive apparatus 50 are provided as aircraft electricactuator drive apparatuses.

The aileron drive apparatus 40 has the electric actuator 41, an aileroncontrol device 42, and the flywheel battery unit 60. The electricactuator 41 includes the electric motor 43.

In the present embodiment, the aileron control device 42 is disposedtogether with the flight control computer 33 within the body 104 of theairframe 101. The aileron control device 42 and the flight controlcomputer 33 are connected to the low-voltage bus 16, and are configuredto operate using electric power from the low-voltage bus 16.

The flight control computer 33 has a CPU (Central Processing Unit), aRAM (Random Access Memory), a ROM (Read Only Memory), and the like, andis provided as an integrated control unit related to a flight of theaircraft 100. The flight control computer 33 is configured to output apredetermined control signal, based on a signal that is output from acontrol stick (not shown) or the like. For example, if a command foroperating an aileron 105L is given from the control stick to the flightcontrol computer 33, the flight control computer 33 outputs a controlsignal for operating the aileron drive apparatus 40 to the aileroncontrol device 42.

The aileron control device 42 is provided as an electric actuatorcontrol device that controls the electric actuator 41. The aileroncontrol device 42 is formed using a CPU, a RAM, a ROM, and the like, andis configured to generate a control signal for causing the electricactuator 41 to perform an operation in accordance with the controlsignal from the flight control computer 33. The aileron control device42 generates a control signal for driving the electric actuator 41,based on the control signal that is output from the flight controlcomputer 33 and motor signals from the electric motor 43.

The aileron control device 42 has interface units 421 and 422, a targetcurrent calculation unit 423, a PWM command generation unit 424, and aprotection circuit 425.

The interface unit 421 receives the control signal that is output fromthe flight control computer 33, and outputs this control signal to thetarget current calculation unit 423. The target current calculation unit423 calculates a target current value based on feedback control using arotational position signal, a rotational speed signal, and a currentsignal of the electric motor 43.

Note that the aforementioned rotational position signal is a signalindicating the position of a rotary shaft of the electric motor 43. Theaforementioned rotational speed signal is a signal indicating therotational speed of the rotary shaft of the electric motor 43. Theaforementioned current signal is a signal indicating the value of acurrent that flows through the electric motor 43. The aforementionedtarget current value corresponds to the value of a current to be appliedto the electric motor 43. The calculated target current value is outputto the PWM command generation unit 424.

The PWM command generation unit 424 performs pulse width modulationcontrol (PWM control) in order that the same current as that of thetarget current value flows through the electric motor 43. The PWMcommand generation unit 424 generates a PWM control signal to be outputto a later-described motor driver 45 in the electric actuator 41, basedon the target current value, and outputs this PWM control signal to theinterface unit 422. The interface unit 422 outputs the PWM controlsignal to the electric actuator 41.

The interface unit 422 is configured to receive, from the motor driver45, the rotational position signal, the rotational speed signal, and thecurrent signal of the electric motor 43. The interface unit 422 outputsthe aforementioned rotational position signal, rotational speed signal,and current signal to the target current calculation unit 423 and theprotection circuit 425. The interface unit 422 also outputs theaforementioned rotational speed signal and current signal to theflywheel battery control device 35.

The electric actuator 41 is connected to the FCS high-voltage bus 14,and is configured to be driven using electric power from the main powerunit 21. In the present embodiment, the electric actuator 41 isconfigured to be driven using electric power that is temporarily appliedfrom the flywheel battery 27. In the present embodiment, the electricactuator 41 and the aileron control device 42 are separately disposed.Specifically, the electric actuator 41 is disposed in the main wing102L, and the aileron control device 42 is disposed in the body 104.Furthermore, the electric actuator 41 and the aileron control device 42are communicably connected to each other via a communication line 44.

The electric actuator 41 has the electric motor 43, the motor driver 45,and a motion conversion mechanism 46.

In the present embodiment, the electric motor 43, the motor driver 45,and the motion conversion mechanism 46 are all disposed in the main wing102L, and are all disposed adjacent to one another.

The motor driver 45 is provided in order to distribute electric power tothe electric motor 43, based on the PWM control signal given from theaileron control device 42.

The motor driver 45 has interface units 451 and 452, a centralprocessing unit 453, a power distribution processing unit 454, aprotection circuit 455, and a three-phase inverter circuit 456.

The interface unit 451 is communicably connected to the interface unit422 in the aileron control device 42 via the communication line 44. Theinterface unit 452 is communicably connected to the central processingunit 453.

The central processing unit 453 is formed using a PLD (ProgrammableLogic Device), for example. The central processing unit 453 isconfigured to output, to the power distribution processing unit 454, thePWM control signal received via the interface unit 422. The centralprocessing unit 453 is also connected to the interface unit 452, and isconfigured to output, to the interface unit 451, the motor signals suchas the rotational position signal, the rotational speed signal, and thecurrent signal of the electric motor 43 that are given to the interfaceunit 452.

The power distribution processing unit 454 is formed using a PLD(Programmable Logic Device), for example. The power distributionprocessing unit 454 operates based on the PWM control signal. The powerdistribution processing unit 454 thereby outputs, to the three-phaseinverter circuit 456, a control signal for selectively switching sixswitching elements 457 of the three-phase inverter circuit 456 from anoff state to an on state.

The three-phase inverter circuit 456 has six switching elements 457, asmentioned above. Each switching element 457 is an IGBT (Insulated GateBipolar Transistor), for example. The switching elements 457 areconnected to the FCS high-voltage bus 14 and a GND (grounding point),and are also connected to a stator coil of the electric motor 43. Theswitching elements 457 are also connected to the power distributionprocessing unit 454. The switching elements 457 are in a conductivestate while being given the control signal from the power distributionprocessing unit 454, and can cause a high-voltage (270-V) current foroperating the electric motor 43 to flow.

A current detection unit 458 is connected to the three-phase invertercircuit 456. The current detection unit 458 is configured to be able todetect a current that flows through the electric motor 43. A currentsignal from the current detection unit 458 is output to the interfaceunit 452.

In the present embodiment, the electric motor 43 is a three-phase ACmotor, and is driven to rotate by electric power applied from thethree-phase inverter circuit 456. The electric motor 43 has a rotationalangle detection sensor 431 that detects the rotational angle of therotary shaft of the electric motor 43. The rotational angle detectionsensor 431 is a resolver, for example, and detects the position and thespeed of the rotary shaft of the electric motor 43. A rotationalposition signal and a rotational speed signal from the rotational angledetection sensor 431 are output to the interface unit 452.

The interface unit 452 outputs the rotational position signal, therotational speed signal, and the current signal of the electric motor 43to the central processing unit 453. Thus, the rotational positionsignal, the rotational speed signal, and the current signal of theelectric motor 43 are output to the interface unit 422 in the aileroncontrol device 42 via the central processing unit 453 and the interfaceunit 451.

The electric motor 43 operates using electric power applied from thethree-phase inverter circuit 456 in the motor driver 45, as mentionedabove, and the rotary shaft of the electric motor 43 rotates by apredetermined amount. The rotational motion of the rotary shaft isoutput to the motion conversion mechanism 46.

The motion conversion mechanism 46 is provided in order to convert therotational motion of the rotary shaft of the electric motor 43 intolinear motion. The motion conversion mechanism 46 includes a ball screwmechanism, for example, and has a movable portion 461 including a malescrew member. With a rotation of the rotary shaft of the electric motor43, the movable portion 461 is displaced linearly. The movable portion461 is connected to the aileron 105L, and the aileron 105L is displacedwith the displacement of the movable portion 461.

Next, a configuration of the flywheel battery control device 35 in theflywheel battery unit 60 will be described. The flywheel battery controldevice 35 is provided as a secondary power supply control device(electricity storage control device) for controlling the flywheelbattery 27, and is disposed in the body 104. The flywheel batterycontrol device 35 is connected to the low-voltage bus 16 and operatesusing electric power from the low-voltage bus 16. In the presentembodiment, the flywheel battery control device 35 operates the flywheelbattery 27 in accordance with the state of power consumption by theelectric motor 43 (necessary electric power required for the operationof the electric motor 43) connected to the FCS high-voltage bus 14. Inthe present embodiment, the flywheel battery control device 35 detects(predicts) a load of the electric motor 43 in the electric actuator 41,and operates the flywheel battery 27 based on a result of thisdetection.

The flywheel battery control device 35 has a CPU, a RAM, a ROM, and thelike. In the present embodiment, the flywheel battery control device 35and the aileron control device 42 are integrated with each other. Thatis to say, the flywheel battery control device 35 and the aileroncontrol device 42 are formed using the same CPU, RAM, and ROM, and sharethe rotational speed signal and the current signal of the electric motor43.

The flywheel battery control device 35 has an operation setting unit351, a power map storage unit 352, and an interface unit 353.

The power map storage unit 352 stores a map indicating properties ofnecessary electric power at the time of driving the electric motor 43 inthe electric actuator 41. An example of this map is shown in FIG. 4.FIG. 4 is a diagram showing an exemplary map for illustrating propertiesof necessary electric power at the time of driving the electric motor 43in the electric actuator 41.

Referring to FIGS. 3 and 4, the upper graph in FIG. 4 indicates acontrol surface angle (angle of inclination) of the aileron 105L withrespect to the main wing 102L. This graph indicates a relationshipbetween time and the control surface angle, with the horizontal axisindicating time and the vertical axis indicating the control surfaceangle of the aileron 105L. The lower graph in FIG. 4 indicates thecurrent value required by the electric motor 43. This graph indicates arelationship between time and the value of the current flowing throughthe electric actuator 41, with the horizontal axis indicating time andthe vertical axis indicating the value of the current flowing throughthe electric actuator 41.

The graphs in FIG. 4 indicate changes in the case where the controlsurface angle of the aileron 105L is changed by a predetermined value,thereafter the control surface angle of the aileron 105L is maintainedat a fixed value during a fixed time period, and then the aileron 105Lis returned again to its original position.

If an operation is performed as indicated by these graphs, the electricmotor 43 is instantaneously driven by a large current (inertialacceleration current) that exceeds a predetermined threshold value Thwhen the aileron 105L begins to operate, then is driven by a currentthat increases in proportion to the amount of elapsed time while thecontrol surface angle of the aileron 105L is increased, and stops beingdriven when the control surface angle of the aileron 105L reaches thetarget value. When the electric motor 43 stops being driven, apredetermined holding current H1 is applied to the electric motor 43 anda force is thereby generated that holds the attitude of the aileron105L. Furthermore, when the operation of the aileron 105L is started inorder to return the control surface angle of the aileron 105L to itsoriginal value, the electric motor 43 is instantaneously driven by alarge current (inertial acceleration current) that exceeds thepredetermined threshold value Th, and thereafter operates so as togenerate a regenerative current. The aileron 105L is thereby returned toits original position.

The operation setting unit 351 is configured to set an operation thatthe flywheel battery 27 is to be caused to perform. Specifically, theoperation setting unit 351 receives, from the interface unit 422, therotational speed signal and the current signal of the electric motor 43that serve as information which is input to the interface unit 422 fromthe motor driver 45. The operation setting unit 351 then references themap (map shown in FIG. 4) stored in the power map storage unit 352 andthe target current value. The operation setting unit 351 thereby detects(estimates) the operation performed by the electric motor 43, based onthe present rotational speed and current value of the electric motor 43.That is to say, the operation setting unit 351 detects the currentrequired by the electric motor 43 using feedforward control.

If it is estimated that the current value required by the electric motor43 exceeds the predetermined threshold value Th, the operation settingunit 351 generates a control signal for supplying electric power fromthe flywheel battery 27 to the electric motor 43 (FCS high-voltage bus14). The control signal in this case is a signal for commanding that acurrent corresponding to the difference between the current valuerequired by the electric motor 43 and the aforementioned threshold valueTh is supplied from the flywheel battery 27 to the electric motor 43.The operation setting unit 351 outputs this control signal to theinterface unit 275 in the flywheel battery 27 via the interface unit353.

On the other hand, if the current value required by the electric motor43 is smaller than or equal to the predetermined threshold value Th, theoperation setting unit 351 generates a control signal for causing theflywheel battery 27 to store electricity, and outputs this controlsignal to the interface unit 275 in the flywheel battery 27 via theinterface unit 353.

Referring to FIGS. 1 to 3, the spoiler drive apparatus 50 has theelectric actuator 51 and the spoiler control device 52.

The spoiler control device 52 is connected to the low-voltage bus 16 andoperates using electric power from the low-voltage bus 16. The spoilercontrol device 52 is disposed in the body 104. The spoiler controldevice 52 has a configuration that is similar to that of the aileroncontrol device 42, and gives a PWM control signal to the electricactuator 51, based on a control signal from the flight control computer33.

The electric actuator 51 is connected to the FCS high-voltage bus 14,and operates using electric power from the FCS high-voltage bus 14. Theelectric actuator 51 has a configuration that is similar to that of theelectric actuator 41 for an aileron, and is connected to the spoiler106L. This electric actuator 51 is driven based on the PWM controlsignal from the spoiler control device 52, and thereby operates thespoiler 106L.

The outline configuration of the aircraft 100 is as described above.Next, an exemplary operation in the electric power system 1 in theaircraft 100 will be described.

FIG. 5 is a flowchart for illustrating an exemplary flow of processingin the aileron control device 42. Note that when a description is givenbelow with reference to the flowchart, diagrams other than the flowchartwill also be referred to as appropriate.

Referring to FIG. 5, the target current calculation unit 423 in theaileron control device 42 initially reads the control signal from theflight control computer 33 (step S11). Next, the target currentcalculation unit 423 reads the motor signals (rotational positionsignal, rotational speed signal, and current signal) of the electricmotor 43 that are output from the motor driver 45 (step S12).

Next, the target current calculation unit 423 in the aileron controldevice 42 calculates the target current value for the electric motor 43(step S13). Next, the PWM command generation unit 424 in the aileroncontrol device 42 generates the PWM control signal such that a currentof the same value as the target current value flows through the electricmotor 43 (step S14). Next, the aileron control device 42 outputs the PWMcontrol signal to the motor driver 45 (step S15). The aileron controldevice 42 repeatedly performs the above processing.

Next, an exemplary flow of processing in the flywheel battery controldevice 35 will be described. FIG. 6 is a flowchart for illustrating anexemplary flow of processing in the flywheel battery control device 35.Referring to FIG. 6, the operation setting unit 351 in the flywheelbattery control device 35 initially reads the motor signals (rotationalspeed signal and current signal) of the electric motor 43 that areoutput from the motor driver 45 (step S21).

Next, the operation setting unit 351 references the rotational speedsignal and the current signal of the electric motor 43, as well as themap stored in the power map storage unit 352, and detects (estimates)the operation performed by the electric motor 43. That is to say, theflywheel battery control device 35 calculates the target current valuefor the electric motor 43 (step S22). Next, the operation setting unit351 determines whether or not a power generating operation by theflywheel battery 27 is necessary (step S23). Specifically, if thecurrent value required by the electric motor 43 exceeds the thresholdvalue Th (YES in step S23), the operation setting unit 351 outputs, tothe flywheel battery 27, the control signal for outputting electricpower from the flywheel battery 27 to the electric motor 43 (FCShigh-voltage bus 14) (step S24). That is to say, the operation settingunit 351 causes the flywheel battery 27 to perform the power generatingoperation if the necessary electric power required by the electric motor43 exceeds a predetermined value.

More specifically, the operation setting unit 351 outputs, to theflywheel battery 27, the control signal for causing the firstinverter/converter 273 to perform an operation of converting AC powerinto DC power. Consequently, the AC power from the motor generator 272that is being driven due to a rotation of the flywheel 271 is convertedinto DC power by the first inverter/converter 273. The DC power that isoutput from the first inverter/converter 273 is supplied together withDC power from the main power unit 21 to the electric motor 43 via theFCS high-voltage bus 14 and the three-phase inverter circuit 456.

On the other hand, if the current value required by the electric motor43 is smaller than or equal to the predetermined threshold value Th (NOin step S23), the operation setting unit 351 outputs, to the flywheelbattery 27, a control signal for causing the flywheel battery 27 toperform an electricity storing operation (step S25). That is to say, theoperation setting unit 351 causes the flywheel battery 27 to perform theelectricity storing operation if the necessary electric power requiredby the electric motor 43 is smaller than or equal to a predeterminedvalue.

More specifically, the operation setting unit 351 outputs, to theflywheel battery 27, the control signal for causing the secondinverter/converter 274 to perform an operation of converting DC powerinto AC power. Consequently, the second inverter/converter 274 operatesas a three-phase inverter circuit, and drives the motor generator 272using electric power from the first high-voltage bus 11. The rotationalforce is thereby applied to the flywheel 271, and accumulation ofkinetic energy by the flywheel 271, that is to say, the electricitystoring operation by the flywheel battery 27 is performed.

Note that if the load of the electric actuator 41 is small, the flywheelbattery 27 may be caused to perform the electricity storing operation byapplying electric power from the FCS high-voltage bus 14 to the flywheelbattery 27. If the load such as the air conditioner 31 or the likeconnected to the first high-voltage bus 11 is large, electric power fromthe flywheel battery 27 may be output to the first high-voltage bus 11.

Electric power may be constantly transmitted and received between theflywheel battery 27 and the first high-voltage bus 11, and electricpower may be constantly transmitted and received between the flywheelbattery 27 and the FCS high-voltage bus 14.

As described above, with the electric power system 1 according to thepresent embodiment, the first high-voltage bus 11 is configured suchthat it is possible for the first high-voltage bus 11 to always beconnected to the flywheel battery 27 and the main power units 22 and 23that serve as two or more types of power supply devices having differentforms. The FCS high-voltage bus 14 is configured such that it ispossible for the FCS high-voltage bus 14 to always be connected to theflywheel battery 27 and the main power unit 21 that serve as two or moretypes of power supply devices having different forms. With thisconfiguration, when the electric motor 43 in the electric actuator 41operates for attitude control for the aircraft 100, the electric motor43 temporarily requires a large current (inertial acceleration current)in order to start operating with a large torque that can act against alarge resisting force such as air resistance received by the aileron105L. In this case, the aforementioned large current can be supplied tothe electric motor 43 by electric power being output to the electricmotor 43 simultaneously from the flywheel battery 27 and the main powerunit 21 having a different form via the FCS high-voltage bus 14.Accordingly, the aforementioned large current does not need to begenerated with one main power unit 21. For this reason, the size of themain power unit 21 can be further reduced. Furthermore, the main powerunits 21, 22, and 23 and the flywheel battery 27 are separatelydisposed. Thus, line loss (power loss) in the first high-voltage bus 11and the FCS high-voltage bus 14 can be further reduced. In particular,since the bus length in the aircraft 100 is extremely long, a reductionin the line loss has a significantly large effect. Consequently, thesize (weight) of the power supply devices (main power units 21, 22, and23 and flywheel battery 27) can be further reduced. As a result, theaircraft electric power system 1 can be provided with which a largeamount of electric power can be supplied to the electric motor 43 in theelectric actuator 41 and an increase in the size of the main power units21, 22, and 23 and the like can be suppressed.

With the electric power system 1, if the electric motor 43instantaneously requires a large amount of electric power, a largeamount of electric power can be supplied to the electric motor 43 due tocooperation between the main power unit 21 and the flywheel battery 27.If the electric power required by the electric motor 43 is relativelysmall, the electric motor 43 can be operated using electric powergenerated by the main power unit 21. With this configuration, the ratedoutput of the main power unit 21 can be further reduced. Accordingly,the size and weight of the main power unit 21 and the engine 103L fordriving the main power unit 21 can be further reduced.

With the electric power system 1, the flywheel battery control device 35controls the operation of the flywheel battery 27 in accordance with thestate of power consumption by the electric motor 43 connected to the FCShigh-voltage bus 14. With this configuration, the flywheel batterycontrol device 35 can set the amount of electricity discharge from theflywheel battery 27 in accordance with the state of power consumption bythe electric motor 43. Thus, electric power stored in the flywheelbattery 27 can be used more efficiently. Consequently, the flywheelbattery 27 does not need to store an unnecessarily large amount ofelectric power. Accordingly, the size of the flywheel battery 27 can befurther reduced.

With the electric power system 1, the flywheel battery control device 35causes the flywheel battery 27 to perform an electricity dischargingoperation if the necessary electric power required by the electric motor43 exceeds a predetermined value. With this configuration, if a largeamount of electric power that exceeds the maximum value of the electricpower that can be supplied to the electric motor 43 from the main powerunit 21 needs to be supplied to the electric motor 43, the flywheelbattery control device 35 can cause the flywheel battery 27 to performthe electricity discharging operation. Thus, necessary electric powercan be stably supplied to the electric motor 43, and the rated output ofthe main power unit 21 can be further reduced.

With the electric power system 1, the flywheel battery control device 35can cause the flywheel battery 27 to perform the electricity storingoperation if the necessary electric power required by the electric motor43 is smaller than or equal to the predetermined value. With thisconfiguration, the flywheel battery control device 35 can cause theflywheel battery 27 to perform the electricity storing operation whileelectric power supply to the electric motor 43 is not necessary.

With the electric power system 1, the first high-voltage bus 11 and theFCS high-voltage bus 14 are connected such that electric power can betransmitted and received therebetween. With this configuration, thepower supply path to the electric motor 43 can be formed into a smartgrid. That is to say, the power supply path to the electric motor 43 canbe multiplexed. Consequently, a situation where the power supplycapacity is significantly lost due to a failure of one main power unit21 or the like can be suppressed. Accordingly, a more reliable electricpower system 1 in which electric power can be more reliably supplied tothe electric motor 43 can be realized. Furthermore, for example, if aconfiguration in which AC power supply buses are electrically connectedto each other is employed, it is difficult to adjust the power supplyphase and the voltage level for balancing the load of electric poweramong the AC power supply buses. In contrast, with the configuration inwhich the first high-voltage bus 11 and the FCS high-voltage bus 14,which are DC buses, are connected to each other as in the presentembodiment, such an adjustment operation that requires time and effortis not necessary, and a smart grid can be realized with a simplerconfiguration.

The electric power system 1 is provided with the FCS high-voltage bus 14dedicated to the flight control devices (electric actuators 41 and 51,etc.). With this configuration, the influence of voltage fluctuationscaused by devices other than the flight control devices reaching theflight control devices can be suppressed. Consequently, electric powercan be more reliably supplied stably to the flight control devices.Furthermore, with the configuration in which DC power is supplied to theelectric actuators 41 and 51, line loss (power loss) can be furtherreduced as compared with the case of supplying AC power to the electricactuators 41 and 51.

With the electric power system 1, the first high-voltage bus 11 and theFCS high-voltage bus 14 are connected to each other such that electricpower can be transmitted and received therebetween, via the flywheelbattery 27 capable of storing and discharging electricity. With thisconfiguration, the flywheel battery 27 disposed between the firsthigh-voltage bus 11 and the FCS high-voltage bus 14 functions as anaccumulator, and can thereby suppress an occurrence of an unstablevoltage fluctuation caused due to interchange of electric power betweenthe first high-voltage bus 11 and the FCS high-voltage bus 14.

With the electric power system 1, the flywheel battery 27 cantemporarily convert the electric power from one of the firsthigh-voltage bus 11 and the FCS high-voltage bus 14 into the kineticenergy of the flywheel 271, thereafter convert this kinetic energy intoelectric power, and then output the electric power to other buses. Withthis configuration, an occurrence of a short circuit between the firsthigh-voltage bus 11 and the FCS high-voltage bus 14 can be suppressed.That is to say, electric insulation between the first high-voltage bus11 and the FCS high-voltage bus 14 can be realized. Accordingly, anoccurrence of an unstable voltage fluctuation caused due to interchangeof electric power between the DC buses 11, 14 can be more reliablysuppressed.

With the electric power system 1, the main power units 22 and 23 areconnected to the first high-voltage bus 11. With this configuration,even if a failure occurs in one of the main power units 22 and 23,electric power can be supplied from the other of the main power units 22and 23. Accordingly, electric power can be more reliably supplied to theelectric devices such as the air conditioner 31.

With the aileron drive apparatus 40 according to the present embodiment,the flywheel battery 27 can temporarily supply electric power to theelectric actuator 41 while electric power from the main power unit 21 isapplied to the electric actuator 41. With this configuration, asmentioned above, a large current (inertial acceleration current) istemporarily required in order that the electric actuator 41 begins tooperate. In this case, the flywheel battery 27 can supply electric powerto the electric actuator 41. Accordingly, the aforementioned largecurrent can be supplied to the electric actuator 41 as a result ofelectric power being output to the electric actuator 41 simultaneouslyfrom the main power unit 21 and the flywheel battery 27. Therefore, thelarge current does not need to be generated using only the main powerunit 21. Accordingly, the rated output of the main power unit 21 doesnot need to be increased to the extent that the main power unit 21 caninstantaneously supply a required large current to the electric actuator41, and the rated output can be further reduced. Thus, the size (weight)of the main power unit 21 and the engine 103L serving as a motor fordriving the main power unit 21 can be further reduced. As a result, theaileron drive apparatus 40 can be provided with which a large amount ofelectric power can be supplied to the electric actuator 41 and anincrease in the size of the main power unit 21 can be suppressed.

With the aileron drive apparatus 40, the flywheel battery control device35 can set the amount of electricity discharge from the flywheel battery27 in accordance with the state of power consumption by the electricactuator 41. Thus, electric power generated by the flywheel battery 27can be used more efficiently. Consequently, the flywheel battery 27 doesnot require an unnecessarily large rated output. Accordingly, the sizeof the flywheel battery 27 can be further reduced.

With the aileron drive apparatus 40, the flywheel battery control device35 detects the load of the electric actuator 41, and operates theflywheel battery 27 based on a result of the detection. With thisconfiguration, an output appropriate for the load of the electricactuator 41 can be supplied from the flywheel battery 27 to the electricactuator 41. In the present embodiment, the flywheel battery controldevice 35 supplies electric power required by the electric actuator 41to the electric actuator 41 using feedforward control, and a voltagedecrease in the electric actuator 41 can thereby be more reliablysuppressed.

In the aileron drive apparatus 40, the flywheel battery control device35 and the motor driver 45 are separately disposed, and are communicablyconnected via the communication line 44. With this configuration, theflywheel battery control device 35 and the motor driver 45 can beseparately disposed. Thus, the flywheel battery control device 35 andthe motor driver 45 can be maintained individually. Accordingly, themaintainability of the aileron drive apparatus 40 can be furtherenhanced.

With the aileron drive apparatus 40, the motion conversion mechanism 46,the electric motor 43, and the motor driver 45 are disposed adjacent toone another. With this configuration, as a result of adjacentlydisposing the motion conversion mechanism 46, the electric motor 43, andthe motor driver 45, the motion conversion mechanism 46, the electricmotor 43, and the motor driver 45 can be maintained collectively.Accordingly, the maintainability of the aileron drive apparatus 40 canbe further enhanced.

With the aileron drive apparatus 40, the aileron control device 42 andthe flywheel battery control device 35 are formed integrally. With thisconfiguration, the aileron control device 42 and the flywheel batterycontrol device 35 can share information, and the control accuracy forthe electric actuator 41 and the control accuracy for the flywheelbattery 27 can be further increased. Furthermore, the overall size ofthe aileron control device 42 and the flywheel battery control device 35can be reduced.

With the aileron drive apparatus 40, the flywheel battery 27 is of aninverter-controlled type. With this configuration, since regenerativeelectric power from the electric actuator 41 can be returned to theflywheel battery 27, energy saving in the electric actuator 41 can berealized through a further increase in electric power use efficiency.Moreover, a reduction in the amount of heat generated in the electricactuator 41 can be realized.

With the aileron drive apparatus 40, the flywheel battery 27 can supplyelectric power to the electric actuator 41 by converting kinetic energygenerated by a rotation of the flywheel 271 into electric power. Withthis configuration, a large current can be instantaneously applied fromthe flywheel battery 27 to the electric actuator 41 when a large currentneeds to flow through the electric actuator 41, by rotating the flywheel271 and storing kinetic energy in the flywheel 271 in advance. That isto say, the flywheel battery 27 with a high responsiveness with respectto an electricity discharge request can be realized.

With the aileron drive apparatus 40, a large current can be applied fromthe main power unit 21 and the flywheel battery 27 to the electricactuator 41 for the flight control system that receives a large drivingresistance during a flight of the aircraft 100. Accordingly, theelectric actuator 41 can be operated with a larger force.

Second Embodiment

FIG. 7 is a schematic view for illustrating a main part of a secondembodiment of the present invention. Referring to FIG. 7, in the presentembodiment, an aileron/spoiler control device 55 is provided in place ofthe aileron control device 42 and the spoiler control device 52. Theaileron/spoiler control device 55 is configured to control operations ofthe plurality of electric actuators 41 and 51.

Note that configurations that are different from those in the aboveembodiment will be mainly described below, and configurations that aresimilar to those in the above embodiment will be given similar referencenumerals and will not be described in detail.

The aileron/spoiler control device 55 generates a PWM control signal fordriving the electric motor 43 in the electric actuator 41 for anaileron, based on a control signal from the flight control computer 33,and outputs this PWM control signal to the motor driver 45 in theelectric actuator 41. Similarly, the aileron/spoiler control device 55generates a PWM control signal for driving an electric motor 43′ in theelectric actuator 51 for a spoiler, based on a control signal from theflight control computer 33, and outputs this PWM control signal to amotor driver 45′.

At the time of the aforementioned control, the aileron/spoiler controldevice 55 generates the PWM control signal by using feedback controlusing a rotational position signal, a rotational speed signal, and acurrent signal of the electric motor 43 in the electric actuator 41 foran aileron. Similarly, the aileron/spoiler control device 55 generatesthe PWM control signal by using feedback control using a rotationalposition signal, a rotational speed signal, and a current signal of theelectric motor 43′ in the electric actuator 51 for a spoiler. Theaileron/spoiler control device 55 outputs the rotational speed signaland the current signal of the electric motors 43 and 43′ to the flywheelbattery control device 35.

The operation setting unit 351 in the flywheel battery control device 35controls operations of the flywheel battery 27 in accordance with thestate of power consumption by loads of the plurality of electric motors43 and 43′ connected to the FCS high-voltage bus 14. Specifically, theoperation setting unit 351 in the flywheel battery control device 35receives the rotational speed signal and the current signal of theelectric motors 43 and 43′ from the aileron/spoiler control device 55.The operation setting unit 351 then references the rotational speedsignal and the current signal, as well as maps stored in the power mapstorage unit 352, and detects (estimates) a total value of necessarycurrent values (electric power amounts) for operations of the respectiveelectric motors 43 and 43′.

Note that a map corresponding to the electric motor 43 in the electricactuator 41 for an aileron and a map corresponding to the electric motor43′ in the electric actuator 51 for a spoiler are provided. These mapsare stored in the power map storage unit 352. The map corresponding tothe electric motor 43′ in the electric actuator 51 for a spoiler is setsimilarly to the map corresponding to the electric motor 43 in theelectric actuator 41 for an aileron shown in FIG. 4.

The operation setting unit 351 detects the total value of the electricpower amounts required by the respective electric motors 43 and 43′ byperforming the above processing, and determines based on this totalvalue whether or not a power generating operation by the flywheelbattery 27 is necessary. If the operation setting unit 351 determinesthat the power generating operation by the flywheel battery 27 isnecessary, the operation setting unit 351 controls the firstinverter/converter 273 so as to cause the flywheel battery 27 to performthe power generating operation.

On the other hand, if the operation setting unit 351 determines that thepower generating operation by the flywheel battery 27 is not necessary,the operation setting unit 351 controls the second inverter/converter274 so as to cause the flywheel battery 27 to perform an electricitystoring operation (rotational operation of the flywheel 271).

As a result, according to the present embodiment, the following effectscan be achieved in addition to the effects of the first embodiment. Thatis to say, the flywheel battery control device 35 can operate theflywheel battery 27 based on the total value of the necessary electricpower for operations of the respective electric actuators 41 and 51.With this configuration, even if the electric actuators 41 and 51operate simultaneously, a larger amount of electric power than theamount applied from the main power unit 21 can be supplied to theelectric actuators 41 and 51. Furthermore, the electric power applied tothe electric actuators 41 and 51 can be collectively controlled by oneflywheel battery control device 35. Thus, the flywheel battery controldevice 35 can control the flywheel battery 27 using combined informationfrom the electric actuators 41 and 51. Accordingly, the flywheel batterycontrol device 35 can perform electric power control for the electricactuators 41 and 51 with more accuracy.

According to the present embodiment, the aileron/spoiler control device55 can control operations of the electric actuators 41 and 51, andoutput (rotational speed signal and current signal) signals forspecifying the operational state of the electric actuators 41 and 51 tothe flywheel battery control device 35. With this configuration, theaileron/spoiler control device 55 can configure an integrated systemhaving a function of controlling the electric actuators 41 and 51 and afunction of giving data for controlling the electric actuators 41 and 51to the flywheel battery control device 35.

Third Embodiment

Next, a third embodiment of the present invention will be described.FIG. 8 is a schematic view for illustrating a main part of a thirdembodiment of the present invention. Referring to FIG. 8, in the thirdembodiment, flywheel batteries 27 and 27A are provided respectively forthe electric actuators 41 and 51. Specifically, an electric power system1A further has the flywheel battery 27A and a flywheel battery controldevice 35A in relation to the spoiler control device 52. Thus, furtherdecentralized arrangement of power supplies is realized as a result ofprovision of the flywheel battery 27A in addition to the flywheelbattery 27, and a further increase in electric power use efficiency isthereby achieved.

The flywheel battery control device 35A has a configuration that issimilar to that of the flywheel battery unit 35. Specifically, theflywheel battery control device 35A has an operation setting unit 351A,a power map storage unit 352A, and an interface unit 353A.

The flywheel battery 27A has a configuration that is similar to that ofthe flywheel battery 27. Specifically, the flywheel battery 27A has aflywheel 271A, a motor generator 272A, a first inverter/converter 273A,a second inverter/converter 274A, and an interface unit 275A.

The spoiler control device 52 generates a PWM control signal for drivingthe electric motor 43′ in the electric actuator 51 in the spoiler driveapparatus 50, based on a control signal from the flight control computer33, and outputs this PWM control signal to a motor driver 45′.

At the time of the aforementioned control, the spoiler control device 52generates the PWM control signal by using feedback control using arotational position signal, a rotational speed signal, and a currentsignal of the electric motor 43′ in the electric actuator 51 in thespoiler drive apparatus 50.

The spoiler control device 52 outputs the rotational speed signal andthe current signal of the electric motor 43′ in the electric actuator 51in the spoiler drive apparatus 50 to the operation setting unit 351A inthe flywheel battery control device 35A.

The operation setting unit 351A receives the aforementioned rotationalspeed signal and current signal of the electric motor 43′ from thespoiler control device 52. The operation setting unit 351A thenreferences the rotational speed signal and the current signal, as wellas the map stored in the power map storage unit 352A, and detects(estimates) the electric power amount required by the electric motor43′.

The operation setting unit 351A calculates the necessary electric poweramount required by the electric motor 43′ by performing the aboveprocessing, and determines based on the necessary electric power amountwhether or not a power generating operation by the flywheel battery 27Ais necessary. If the operation setting unit 351A determines that thepower generating operation by the flywheel battery 27A is necessary, theoperation setting unit 351A controls the first inverter/converter 273Aso as to cause the flywheel battery 27A to perform the power generatingoperation.

On the other hand, if the operation setting unit 351A determines thatthe power generating operation by the flywheel battery 27A is notnecessary, the operation setting unit 351A controls the secondinverter/converter 274A so as to cause the flywheel battery 27A toperform an electricity storing operation (rotational operation of theflywheel 271A).

Note that an integrated control unit 70 that integrally controls the twoflywheel battery control devices 35 and 35A may further be provided asshown in FIG. 9. The integrated control unit 70 includes a CPU, a RAM, aROM, and the like. In this case, the integrated control unit 70 outputsa control signal to the two flywheel battery control devices 35 and 35Aas appropriate, in accordance with the operational state of the twoelectric actuators 41 and 51. Thus, electric power interchange betweenthe two flywheel batteries 27 and 27A can be performed.

Fourth Embodiment

FIG. 10 is a schematic view showing a main part of a fourth embodimentof the present invention. Referring to FIG. 10, in the presentembodiment, an integrated control unit 71 and a power control bus 72 areprovided in addition to the configurations in the third embodiment shownin FIG. 8. The integrated control unit 71 includes a CPU, a RAM, a ROM,and the like.

In the present embodiment, the integrated control unit 71 controls theflywheel battery control devices 35 and 35A based on necessary electricpower for electric devices connected to the first high-voltage bus 11and the FCS high-voltage bus 14.

The integrated control unit 71 is connected to the operation settingunits 351 and 351A in the respective flywheel battery control devices 35and 35A via the power control bus 72 and the interface units 353 and353A. The integrated control unit 71 is also connected to electricdevices (air conditioner 31 etc.) to which electric power is suppliedfrom the first high-voltage bus 11, via the power control bus 72. Theintegrated control unit 71 calculates the necessary electric poweramount required by these electric devices, based on values of thecurrent that flows through the electric devices that receive a supply ofelectric power from the first high-voltage bus 11, and the like. Theintegrated control unit 71 also references signals from the operationsetting units 351 and 351A and calculates the necessary electric poweramounts for the respective electric motors 43 and 43′. That is to say,the integrated control unit 71 detects the necessary electric poweramount for the first high-voltage bus 11 and the necessary electricpower amount for the FCS high-voltage bus 14.

The integrated control unit 71 then operates one of the flywheelbatteries 27 and 27A so as to distribute electric power from a bus amongthe first high-voltage bus 11 and the FCS high-voltage bus 14 that has arelatively larger reserve capacity of electric power distribution to oneof the flywheel batteries 27 and 27A. The integrated control unit 71also operates the other of the flywheel batteries 27 and 27A so as tooutput electric power from the other of the flywheel batteries 27 and27A to a bus among the first high-voltage bus 11 and the FCShigh-voltage bus 14 that has a relatively smaller reserve capacity ofelectric power distribution.

Note that electric power from a bus among the first high-voltage bus 11and the FCS high-voltage bus 14 that has a relatively larger reservecapacity of electric power distribution may be supplied to the motorgenerators 272 in the flywheel batteries 27 and 27A, and electric powergenerated by driving these motor generators 272 may be supplied to theother bus.

As a result, according to the present embodiment, the integrated controlunit 71 can operate the flywheel batteries 27 and 27A so as todistribute electric power from one of the first high-voltage bus 11 andthe FCS high-voltage bus 14 having a relatively larger reserve capacityof electric power distribution to the flywheel batteries 27 and 27A. Theintegrated control unit 71 can also cause electric power to be outputfrom the flywheel batteries 27 and 27A to one of the first high-voltagebus 11 and the FCS high-voltage bus 14 having a relatively smallerreserve capacity of electric power distribution. With thisconfiguration, biasing of electric power loads between the firsthigh-voltage bus 11 and the FCS high-voltage bus 14 can be furtherreduced. Accordingly, the rated output of the main power units 21 to 23and the flywheel battery 27 can be further reduced, and consequently,the size and weight of the main power units 21 to 23, the flywheelbattery 27, and the like can be further reduced.

(Modifications)

Although the embodiments of the present invention have been describedabove, needless to say, all modifications, applications, and equivalentsthereof that fall within the claims, for which modifications andapplications would become apparent by reading and understanding thepresent specification, are intended to be embraced in the scope of thepresent invention. For example, the present invention may be modified asbelow for implementation.

(1) The above embodiments have been described, taking, as an example, amode in which the auxiliary power unit and the ram air turbine areprovided. However, this need not be the case. In the above embodiments,since electric power interchange among a plurality of DC buses can beperformed by using a smart grid, at least one of the auxiliary powerunit and the ram air turbine may be omitted. The size and weight of theelectric power system can be further reduced by at least one of theauxiliary power unit and the ram air turbine being omitted.

(2) The above embodiments have been described, taking, as an example, amode in which the main power units, the auxiliary power unit, the ramair turbine, and the motor generator in the flywheel battery are ACpower units. However, this need not be the case. For example, at leastone of the main power units, the auxiliary power unit, the ram airturbine, and the motor generator in the flywheel battery may be a DCpower unit. With this configuration, regarding the DC power unit, anauto transformer rectifier unit (ATRU; AC/DC converter) can be omitted.Consequently, the size and weight of the electric power system can befurther reduced.

(3) In the above embodiments, other kinds of battery capable of storingand discharging electricity, such as a fuel battery or a supercapacitor,may be used in place of the flywheel battery. In the case of using theaforementioned fuel battery, a larger electricity storage capacity canbe reserved, and water discharged from the fuel battery can also bereused.

(4) The above embodiments have been described, taking an aileron and aspoiler as examples of the control surfaces operated by the electricactuators. However, this need not be the case. For example, the presentinvention may be applied to other control surfaces, such as an elevator,a rudder, and a flap. Furthermore, the present invention may be appliedto an electric actuator that drives a leg of landing gear or the likeserving as a device installed in an aircraft.

The present invention can be widely applied to aircraft electricactuator drive apparatuses.

What is claimed is:
 1. An aircraft electric actuator drive apparatus,comprising: an electric actuator driven using electric power from a mainpower unit provided in an aircraft; and a secondary power supply devicecapable of temporarily supplying electric power to the electric actuatorwhile electric power from the main power unit is applied to the electricactuator.
 2. The aircraft electric actuator drive apparatus according toclaim 1, further comprising a secondary power supply control device forcontrolling the secondary power supply device, wherein the secondarypower supply control device operates the secondary power supply devicein accordance with necessary electric power required for an operation ofthe electric actuator.
 3. The aircraft electric actuator drive apparatusaccording to claim 2, wherein the secondary power supply control devicedetects a load of the electric actuator, and operates the secondarypower supply device in accordance with a result of the detection.
 4. Theaircraft electric actuator drive apparatus according to claim 2, whereina plurality of the electric actuators are provided, and the secondarypower supply control device can operate the secondary power supplydevice based on a total value of necessary electric power required foroperations of the respective electric actuators.
 5. The aircraftelectric actuator drive apparatus according to claim 2, furthercomprising a motor driver that distributes electric power to theelectric actuator and outputs a signal for specifying an operationalstate of the electric actuator to the secondary power supply controldevice, wherein the secondary power supply control device and the motordriver are separately disposed.
 6. The aircraft electric actuator driveapparatus according to claim 5, wherein the electric actuator includes amovable portion and an electric motor that operates the movable portion,and the movable portion, the electric motor, and the motor driver aredisposed adjacent to one another.
 7. The aircraft electric actuatordrive apparatus according to claim 2, further comprising an electricactuator control device that controls the electric actuator, and theelectric actuator control device and the secondary power supply controldevice are formed integrally.
 8. The aircraft electric actuator driveapparatus according to claim 2, further comprising an electric actuatorcontrol device that controls the electric actuator, wherein a pluralityof the electric actuators are provided, and the electric actuatorcontrol device can control operations of the electric actuators andoutput a signal for specifying an operational state of the electricactuators to the secondary power supply control device.
 9. The aircraftelectric actuator drive apparatus according to claim 1, wherein thesecondary power supply device has an inverter-controlled power supplydevice.
 10. The aircraft electric actuator drive apparatus according toclaim 1, wherein the secondary power supply device includes a flywheelbattery.
 11. The aircraft electric actuator drive apparatus according toclaim 1, wherein the electric actuator includes an electric actuator fora flight control system for controlling a flight of the aircraft.